Why are all my photos locked?

Okay so I'm a photogapher, and I have a Nikon D3000 camera and it has a flash card of 16 GB. I put in the card into the MacBook Pro but then it says all my photos are locked? What do I do to fix this problem? What good does it do if my photos are "locked"?

Try checking the settings on your camera

Look along the edge of the card, there may be a tiny switch.
If so, move it to the opposite position☺